The Weber test, in which a tuning fork is touched to the midline of the forehead, localizes to the normal ear in people with this condition.
The Rinne test, which tests air conduction vs. bone conduction is positive (normal), though both bone and air conduction are reduced equally.

Sensorineural hearing loss can be mild, moderate, or severe, including total deafness.

The great majority of human sensorineural hearing loss is caused by abnormalities in the hair cells of the organ of Corti in the cochlea. There are also very unusual sensorineural hearing impairments that involve the eighth cranial nerve (the vestibulocochlear nerve) or the auditory portions of the brain. In the rarest of these sorts of hearing loss, only the auditory centers of the brain are affected. In this situation, central hearing loss, sounds may be heard at normal thresholds, but the quality of the sound perceived is so poor that speech can not be understood.

Most sensory hearing loss is due to poor hair cell function. The hair cells may be abnormal at birth, or damaged during the lifetime of an individual. There are both external causes of damage, like noise trauma and infection, and intrinsic abnormalities, like deafness genes.

Sensory hearing loss that results from abnormalities of the central auditory system in the brain is called central hearing impairment. Since the auditory pathways cross back and forth on both sides of the brain, deafness from a central cause is unusual.

This type of hearing loss can also be caused by prolonged exposure to very loud noise, for example, being in a loud workplace without hearing protection, or having headphones set to high volumes for a long period.

Cerebellopontine angle tumour (junction of the pons and cerebellum) (the cerebellopontine angle is the exit site of both the facial nerve(CN7) and the vestibulocochlear nerve(CN8). Patients with these tumors often have signs and symptoms corresponding to compression of both nerves)

Populations living near airports or freeways are exposed to levels of noise typically in the 65 to 75 dbA range. If lifestyles include significant outdoor or open window conditions, these exposures over time can degrade hearing. The U.S. EPA and various states have set noise standards to protect people from these adverse health risks. The EPA has identified the level of 70 db(A) for 24 hour exposure as the level necessary to protect the public from hearing loss (EPA, 1974).

Noise-induced hearing loss (NIHL) typically is centered at 4000 Hz.

The louder the noise is, the shorter the safe amount of exposure is. Normally, the safe amount of exposure is reduced by a factor 2 for every additional 3 dB. For example, the safe daily exposure amount at 85 dB is 8 hours, while the safe exposure at 91 dB(A) is only 2 hours (National Institute for Occupational Safety and Health, 1998). Sometimes, a factor 2 per 5 dB is used.

Personal audio electronics, such as iPods (iPods often reaching 115 decibels or higher), can produce powerful enough sound to cause significant NIHL, given that lesser intensities of even 70 dB can also cause hearing loss.[1]

Hearing loss can be inherited. Both dominant and recessive genes exist which can cause mild to profound impairment. If a family has a dominant gene for deafness, it will persist across generations because it will manifest itself in the offspring even if it is inherited from only one parent. If a family had genetic hearing impairment caused by a recessive gene, it will not always be apparent, as it will have to be passed onto offspring from both parents.
Dominant and recessive hearing impairment can be syndromic or nonsyndromic. Recent gene mapping has identified dozens of nonsyndromic dominant (DFNA#) and recessive (DFNB#) forms of deafness.

Autoimmune disease has only recently been recognized as a potential cause for cochlear damage. Although probably rare, it is possible for autoimmune processes to target the cochlea specifically, without symptoms affecting other organs. Wegener's granulomatosis, an autoimmune condition, may precipitate hearing loss.

Presbycusis is deafness due to loss of perception to high tones, mainly in the elderly. It is considered by some to be a degenerative process, although there has never been a proven link to aging. (See impact of environmental noise exposure above.)

Extremely heavy hydrocodone (Vicodin) abuse is known to cause hearing impairment. There has been speculation radio talk show host Rush Limbaugh's hearing loss was at least in part caused by his admitted addiction to narcotic pain killers, in particular Vicodin and OxyContin.
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There can be damage either to the ear itself or to the brain centers that process the aural information conveyed by the ears.

People who sustain head injury are especially vulnerable to hearing loss or tinnitus, either temporary or permanent.

Exposure to very loud noise (90 dB or more, such as jet engines at close range) can cause progressive hearing loss. Exposure to a single event of extremely loud noise (such as explosions) can also cause temporary or permanent hearing loss. A typical source of acoustic trauma is a too-loud music concert.[3]

Previously, sensorineural hearing loss has been treated with hearing aids, which amplify sounds at preset frequencies to overcome a sensorineural hearing loss in that range; or cochlear implants, which stimulate the cochlear nerve directly.

Some research suggests idebenone alone or combined with vitamin E may delay the onset of hearing loss or perhaps reverse it.[4] Use of these agents for this purpose is considered experimental now.

Some audiologists and ENTs have reported if severe noise-induced hearing loss (exposures exceeding 140dB) is treated immediately (within 24 hours) with a course of steroids, it can often be almost completely reversed.[citation needed] This, however, is a new field without proven success.[5]

Researchers at the University of Michigan report that a combination of high doses of vitamins A, C, and E, and Magnesium, taken one hour before noise exposure and continued as a once-daily treatment for five days, was very effective at preventing permanent noise-induced hearing loss in animals[6]